This invention generally concerns improved machinery for fruit harvesting, and particularly for harvesting high-density orchards, including those in which fruit may be relatively close to the ground. Various aspects of the invention also concern an improved intra-loop conveyor for collecting fruit relatively close to the ground and subsequently elevating same for convenient discharge; an improved fruit detachment mechanism having both constant and oscillatory rotational components of motion for detaching fruit from trees; and an improved output conveyor which is adjustable for desired delivery of the output fruit, and foldable for facilitating non-harvesting transport of a machine utilizing such output conveyor.
Improvements in agricultural practices are in modern times often viewed in an economic context. For example, in the area of fruit production, relatively recent efforts have centered on developing fruit bearing trees, shrubs, or the like and/or orchard techniques which provide the planter with faster returns on planting investments. One type of fruit cultural system being developed by plant breeders and horticulturists for high early fruit yields, and hence early returns on the capital invested to establish the orchard, is known as the meadow orchard. Meadow orchards generally include high-density plantings, with typical in-row spacing such as 0.6 meters to 1.0 meters, with adjacent rows spaced 3 meters on-center.
Meadow orchard techniques (including various elements such as selective pruning, and genetic or chemical control) also typically result in short stature or dwarf trees, with average tree heights of approximately 2 meters. Mechanized harvesters have heretofore been generally adapted for harvesting from fruit trees where relatively lower hanging branches or low-lying fruit were not significant. However, studies have shown for various meadow orchard peach tree varieties that 90% of the fruit may be located within a distance of 0.76 meters to 1.07 meters above the soil surface or ground. Hence, prior harvesters are not generally equipped for operating adequately close to the ground to collect the large quantity of low hanging fruit on meadow orchard type trees.
Another aspect of meadow orchard plantings for which prior harvesters are not generally particularly equipped to handle concerns their relatively high-density characteristics. Such characteristics are a part of the economic advantages offered by the meadow orchard cultural system. The characteristics are to an extent reflected in the relatively close on-center spacing of adjacent rows of such fruit trees, and the even closer in-row spacing of such trees.
Another consequence of modern high-density plantings is that a relatively high quantity of fruit must be handled in a relatively concentrated area, but must be gently handled so as to minimize bruises, cuts, or other damage.